DE3114552A1 - METHOD FOR CATALYTICALLY CRACKING SULFUR AND / OR NITROGEN-BASED HYDROCARBON STARTING MATERIALS - Google Patents

Description

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description

The invention relates to a method for catalytic Cracking of sulfur- and / or nitrogen-containing hydrocarbon feedstocks, with its Help one can produce cracked products with a lower sulfur and / or nitrogen content.

It is well known that the hydrogen pretreatment -jO development of gas oil subjected to the fluidized bed cracking process can improve the quality of the cracked products. From work by Ritter, Blazek and Wallace in "The Oil &. Gas Journal" October 1974, is known that both the quality and quantity of the -J5 cracked gasoline fractions by treatment of gas oil feedstocks with hydrogen before catalytic cracking with zeolite-containing fluidized bed cracking catalysts can be improved.

It is also known from US Pat. No. 3,726,788 that starting materials for the hydrocracking process are advantageously used Hydrogen can be pretreated, with recycled hydrogen being used in excess was obtained from a stage of the hydrocracking process «

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By appropriate pretreatment of sulfur-containing Gas oils with hydrogen can therefore improve the catalytic cracking process; the price for however, the production of sufficient amounts of hydrogen are known for such hydrogen treatment quite high in a typical catalytic cracking process. The amounts of hydrogen used in the normal catalytic cracking processes and are available are relatively small, and the amounts of hydrogen necessary to remove essential Amounts of sulfur or nitrogen are required, must therefore in the known method of external sources. As a result, operate relatively few refineries today have hydrotreated catalytic crackers Raw materials.

The object of the present invention is therefore to provide an improved method for the catalytic cracking of sulfur and / or nitrogen containing hydrocarbon feedstocks to accomplish. Another object of the present invention is to provide a method through the sulfur- and / or nitrogen-containing materials in an economical way with hydrogen treated to prevent catalytic cracking

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significant amounts of sulfur and / or nitrogen impurities to remove.

Another object of the present invention is to provide an integrated method of treatment with hydrogen and the actual catalytic cracking process comprises, at least one a substantial part of that in the hydrogen treatment stage hydrogen used is produced during the catalytic cracking process.

A further aim of the present invention is to provide an economical way of achieving higher yields Show gasoline with a high octane number and a low sulfur content.

According to the invention, this object is achieved by a method for the catalytic cracking of sulfur and / or nitrogen containing Dissolved hydrocarbon starting material, in which the starting material is used to remove the Sulfur and / or nitrogen pollution before the hydrotreated catalytic cracking in the presence of a zeolite-containing cracking catalyst will. The inventive method is characterized in that one

(a) carries out the cracking process with a catalyst with which at least 0.15% by weight of hydrogen, based on the weight of the feedstock, generated in the resulting cracked product stream will,

(b) isolating and withdrawing the hydrogen produced from the cracked product stream; and

(c) the withdrawn hydrogen to treat the output smate rials.

Accordingly, the present invention relates in the broader sense to an integrated method for treatment with Hydrogen and catalytic cracking, in which the hydrotreated feedstocks are cracked in the presence of a cracking catalyst which at least 0.15% by weight, based on the fresh feedstock, of hydrogen in the cracked product stream generated, wherein the hydrogen is separated and recycled to treat the sulfur and / or nitrogen impurities containing starting material.

The method according to the invention sees in particular the Use of a special zeolite-containing cracking catalyst, which has enough hydrogen for advantageous Pretreatment of the raw material produced,

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without the production of unwanted coke and light hydrocarbons at the expense of gasoline yield increases significantly.

In particular, it has been found that when using a typical cracking system with moving catalysts under Use of a zeolite catalyst, in which the zeolite to at least 0.5 wt.% With a metal from the Group silver, copper, nickel and / or manganese is exchanged, an amount of hydrogen during the cracking reaction which is sufficient to remove the sulfur and / or nitrogen impurities in the starting material by pretreatment with hydrogen, which is a by-product of the catalytic cracking reaction, essential to reduce.

The invention is further explained with reference to the figure, which represents a simplified diagram of the basic stages of the method according to the invention.
20th

As the figure shows, a will contain sulfur and / or nitrogen Hydrocarbon feed stream 1 combined with hydrogen stream 2. This united

3
Stream 3, which contains about 0.03 to 0.10 m hydrogen / kg starting material, enters a conventional

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len container 4 a suitable catalyst for hydrotreatment. The hydrocarbon feed usually contains about 0.5 to 5.0 wt.% sulfur and about 0.05 to 1.5 wt.% nitrogen. Usually the sulfur and nitrogen impurities lie as organic complex compounds.

When the combined hydrogen / feedstock stream 3 enters container 4 for hydrogen treatment, it is heated to a temperature in the range of about 300 to 450 ° C and with a catalyst for hydrogen treatment brought into contact, the characteristic! - wise a content of cobalt molybdenum, nickel and / or Has tungsten, suspended on a suitable inorganic oxide as a support material, such as. B. alumina. During the hydrogen treatment stage, the hydrogen combines with the sulfur and / or Nitrogen impurities resulting from the Product stream 5 as hydrogen sulfide and / or ammonia be withdrawn via line 6 with the aid of the separator 7 and the washer 8.

The hydrotreated hydrocarbon feedstock, which now only contains about 0.1 to 1.5% by weight of sulfur and about 0.01 to 1.0% by weight of nitrogen

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holds, is via line 9 in the catalytic cracking plant 10 where the material is brought into contact with a zeolite-containing fluidized bed cracking catalyst will. In the practical implementation of the invention The catalyst used in the process is capable of substantial amounts of hydrogen during the cracking reaction to generate. Zeolite catalysts, which are particularly suitable, contain metals such as silver, copper, nickel and / or manganese. Such catalysts are disclosed in U.S. Patents 3,835,032, 3,985,640 and 3,929,621 has been described. Suitable catalysts contain about 2 to 50% by weight of a crystalline aluminosilicate zeolite, which has been exchanged and / or impregnated with a combination of metal ions and with a suitable inorganic matrix was combined.

The appropriate typical zeolite is a faujasite type such which is replaced with a combination of cations, concentrations are obtained at ausgetausch- ^ΪΘη cations in the range of 1 to 10 wt.%, Wherein the substitutes of Juo _{8 Ag?} 0, NiO,

p and their mixtures exist and, where the remaining cation exchange sites are occupied with magnesium oxide, rare earth oxides and / or hydrogen. Particularly suitable zeolites consist of rare species

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Earth oxides or hydrogen-exchanged faujasites of the Y-type, whereby at the same time 1 to 3 wt.% By CuO, Ag _? 0, Mn ₂ O or NiO are exchanged.

The exchanged faujasite is combined with an inorganic oxide as a base material, which is made from clay, silicon dioxide / aluminum oxide gel, Silicon dioxide and / or alumina. Process for the production of moving catalysts, which in the implementation of the invention Methods that can be used are disclosed in U.S. Patents 3,957,689, 3,912,619, and 3,867 308.

It can be seen from the figure that both cracked products, which are withdrawn via line 11, and combustion gas, which are withdrawn via line 12, are generated in the catalytic cracking system 10. The combustion gas is released in the regeneration stage of the catalyst in which coke and carbon containing impurities are oxidized using a stream of air. Typically, the catalytic cracking process at a cracking temperature in the range of about 490-580 ⁰ C, and the regeneration of the catalyst at a temperature of about 600 is performed to 780 ⁰ C. The stream of cracked product,

that emerges from the catalytic cracking plant is steam at a temperature of about 490 to 580 ° C, which consists of both cracked hydrocarbons and a substantial amount of hydrogen, ie an amount of about 10 to 30 percent by volume hydrogen separated in a distillation column 14. As can be seen from the figure, the separated fractions comprise a current 20 from residue products boiling above about 335 C, a gasoline fraction stream 21 having a boiling range of about 35-220 ⁰ C, a stream 22 of lightweight products having a boiling range of about -42 to +35 C and a stream 23 of dry gas consisting of hydrogen and C ₁ - and C- hydrocarbons with a

Boiling point below about -42 ° C.

It can also be seen from the figure that the dry gas stream 23 from the distillation column 14 is compressed and separated from liquid products which are generated during the compression in the compression plant 25 and that the one emerging from the compression position 25 A gas stream of hydrogen and luminous gases via line 26 with a recirculated hydrogen stream 27 obtained from the washer 8 in

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Compressor 28 is compressed and separated from liquids in the separator 29, was combined, the hydrogen stream 2 being formed. This is then introduced with the sulfur and /
5 or nitrogen contaminated starting material 1 mixed. While a sufficient amount of hydrogen is normally generated in the cracking process according to the invention for the hydrogen treatment, ie the removal of sulfur and / or nitrogen, in cases where the sulfur and / or nitrogen impurities of the starting material are particularly high, the addition of additional hydrogen from an external source may be beneficial.

The invention is explained further below with the aid of examples.

example 1

This example describes a typical process for making the zeolites used in cracking catalysts are used which are suitable for use in the process according to the invention.

300 g of sodium zeolite type Y (Na-Y) with a silicon dioxide / aluminum oxide ratio of 4.9 are 1.2

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1 water, 150 g ammonium sulfate and 11 ml concentrated Mixed sulfuric acid. The mixture is heated to boiling for an hour, then the zeolite recovered, washed twice, repeated the exchange and washing steps once more and then the zeolite dried. In this way; the sodium content of the zeolite is reduced to about 3 to 4% by weight. The zeolite is then exchanged with a solution, the 34 g mixed rare earth chlorides

IQ (RECl) in 1.2 l of water. The amount of solution used is such that the desired concentration of R ^E 2 ° 3 is obtained ^{in the} exchanged zeolite product. The exchanged zeolite is then washed with water and calcined at 760 ° C. for three hours.

The calcined zeolite (RE-Y) is then labeled with (NH.) _? SO. exchanged by mixing the zeolite with a solution of 300 g of ammonium sulfate in 3 l of water. The zeolite is then washed sulfate-free with pure water and then exchanged for the desired metal ions, in this case with copper, by mixing the zeolite with a solution of 16.2 g of CuCl χ 2 HpO in 750 ml of water. The obtained Cu-RE-Y-zeolite containing 2.0 wt.% CuO, and 0 to 18 wt.% RE_O_ and calcined three hours at 538 ⁰ C for.

The ions of copper, silver, manganese and / or nickel in the form of their chlorides, nitrates or other water-soluble salts can be used as metal ions suitable for exchange. The zeolite can be prepared with 5 or without ^RE o ° 3. If no R ^ ₂ O
is used, the exchange stage with REC1 is replaced by the exchange with ammonium sulphate, with all further measures remaining the same. Using the general procedure outlined above, the following zeolites were prepared:

(1) Cu-H-Y (2.0% CuO)

(2) Cu-RE-Y (2.0% CuO + 8.0% RE ₃ O ₃ )

(3) RE-Y (18% RE ₃ O ₃ )

(4) Ag-RE-Y (4% Ag ₃ O + 12% RE ₃ O ₃ ) j

(5) Ag-RE-Y (1% Ag ₃ O + 8 W% RE ₃ O ₃ ) ;
(6) RE-Y (13% RE ₃ O ₃ ) j

Example 2

In this example, the relatively high hydrogen output

P ₀ booty demonstrated with comparable gasoline, coke and luminous gas selectivity that is obtained when using the zeolites described in Example 1. Samples of the corresponding cracking catalyst were prepared by combining the zeolite samples (1) to (5) of Example 1 with a semi-synthetic matrix, the 67 weight

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parts of a 25% silica / alumina hydrogel and contained 33 parts by weight of kaolin clay. The test results are in the tables I and II are compiled and show the results from a stationary, catalytic fluidized bed cracking test facility. The investigations were carried out with hydrothermally deactivated catalysts under the specified Conditions carried out to those to be expected in practice To imitate the performance characteristics of the investigated catalysts. The values clearly show that the Catalysts equipped with copper or silver exchanged zeolites, considerable hydrogen yield result. Another advantage arises from the higher octane number of the gasoline products obtained, compared to a catalyst containing no copper or silver.

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Table I. (2) Cu-RE-Y (3) Re-Y 70.5 72.0 40
4.0
495 ° C Catalyst ( 1) Cu-H-Y 15th 12th 0.35 0.28 Zeolite (wt.%) 22nd % Steam, 1 bar, 12 hours 0.88 0.94 Deactivation at: 81O ⁰ C, 20 wt. stationary fluidized bed test facility 7.1 7.5 Results with a 6.5 6.8 71.5 conditions 10.9 11.5 0.04 WHSV ⁺⁾
Catalytic converter / oil
relationship
temperature
Source material 40 40
4.0 4.0
495 ° C 495 ° C 6.0 6.0 1.4 4.3 4.8 7.8 58.5 61.5 6.8 Weight / h / throughput speed 0.82 0.85 11.5 Results 90.1 88.4 4.9 Conversion (%) 77.8 77.4 5.7 H ₂ (wt.%) 6.0 5.6 59.5 C ₁ + C ₂ (wt.%) 0.83 Total C ₃ (Vol%) 87.8 C ₀ ~ (Vol%) 77.0 Total-C. (Vol%) 5.5 C ₄ (Vol%) ic (Vol%) C ^ ~ gasoline (Vol%) Ratio gasoline / Um
change RON + 0 MON + 0 Coke (wt.%) ⁺⁺⁾

based on the fresh load

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Table II Catalyst:

Ag-RE-Y (4) Ag-RE-Y (S)

RE-Y (6)

Zeolite (wt.%)

10 10

Deactivation at; 810 ° C, 1 bar, 20% by weight / steam in air, 12 hours

Conditions in the test facility:

512 ° C, weight / h / throughput rate: 20 Ratio catalyst / oil: 4.0
Feedstock: West Texas Gas Oil

Conversion (%) H ₂ (wt%)

C ₁ + C ₂ (wt.%)

Total C,

Total-C. (Vol%)

C ^ - gasoline (Vol%)

Ratio C * - gasoline / conversion

octane

RON + O MON + O

64.5 64.5 66.5 0.43 0.21 0.05 0.91 0.92 1.12 6.4 6.6 8.3 5.2 5.5 6.4 10.2 8.1 9.3 5.9 4.2 4.0 3.8 3.4 4.5 52.5 57.0 57.0

Coke (wt.%)

0.82

90.4

76.6

6.2 0.88

89.9

76.5

4.5

0.86

88.8

77.2

4.5

based on the fresh load

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Example 3

Zeolite type Y samples were exchanged with the following ion combinations:
Ag-Mn, Ag-Mn-RE, and Ni-Mg.

(1) A sample of the Ag-Mn-Y zeolite was prepared as follows: 300 g (dry weight) Na-Y was slurried in 2 liters of deionized water at 60.degree. The zeolite was then reslurried in a solution containing 150 g of ammonium sulfate, 1200 ml of deionized water and 21 g of concentrated sulfuric acid and kept boiling for one hour. This exchange was repeated twice and the product obtained was then washed on a filter until the washing solution was free of sulfate. The zeolite was calcined for three hours at 538 C and then slurried in a solution containing 3000 ml of water and 300 g of ammonium sulfate. The slurry was kept boiling for two hours. The zeolite was then washed once with 3 liters of water at 60 ° C., the exchange was repeated once more and the zeolite was then washed with water until the wash water was free of sulfate. One third of the filter cake was then added to 250 ml of a solution containing 25 g of AgNO and 75 g of Mn (NO ₃ ) - and the suspension obtained was added for half an hour

aged at 6O ⁰ C, the zeolite then filtered off and with

Washed 250 ml of water. The zeolite was then calcined for three hours at 760 ° C., an Ag-Mn-Y zeolite (8.6% Ag ₃ O + 1.26% MnO ₃ ) being obtained.

(2) The calcined RE-H-Y zeolite became 5 as follows

produced: 400 g (dry weight) Na-Y were slurried in a solution containing 200 g ammonium sulfate, 26.6 g of concentrated sulfuric acid and 1600 ml of water and the slurry boiled for cine hours

held. It was then filtered off and the 10

exchanged zeolite washed with 1600 ml of water; the exchange was repeated and the zeolite washed again with water until the wash water was free of sulfate. Half of the filter cake obtained was dissolved in 800 ml of a solution containing 26 g of ReCl 6 H χ "0 contained, listed 0 <l

slurried and simmered for two hours. The zeolite was filtered off, washed with 800 ml of hot water and then calcined at 538 ° C. for three hours. The zeolite RE-HY (6% RE ₂ O ₃ )

obtain.
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(3) An Ag-Mn-RE-Y zeolite was prepared as follows:
First, a calcined RE-HY zeolite was prepared as described in Example 3 under (2), with the difference that instead of 6% an exchange concentration

was tration of 12% R ^E 2 ° 3 applies ^ver. The received

Base zeolite was exchanged twice with ammonium sulfate solution, filtered and washed free of sulfate. 50 g (dry weight) of this product were exchanged with 12.5 g of silver nitrate and 12.5 g of manganese nitrate for half an hour at the boiling point in 200 ml of solution. The zeolite was filtered, washed with 300 ml of water and then calcined for three hours at 760 ⁰ C. The Ag-Mn-RE-Y zeolite was obtained (8.0% Ag 0, 1.3% MnO ₂ + 11.0% RE ₂ O ₃ ).

(4) A Ni-Mg-Y zeolite was prepared as follows:
1000 g (dry weight) of Na-Y were washed with water, and then replaced at the boiling temperature three times with ammonium sulfate solution, then washed free of sulphate and then calcined for three hours at 538 ⁰ C. The zeolite was then exchanged twice with ammonium sulfate solution for two hours at boiling temperature and then washed free of sulfate. _{17.5 g NiCl 2} 6 HO and 30.0 g MgCl χ 6 HO in 250 ml of solution were used per 100 g (dry weight) of the zeolite. The slurry was ^{stored at 60 °} C. for half an hour, the filter cake was washed until the washing water was free of chloride, and then calcined for three hours at 760 ° C., a zeolite Ni-Mg-Y (1.35% NiO + 1.30 % MgO).

(5) A calcined RE-Y zeolite (18% RE ₀ O-), which was used in test mixtures with metal-exchanged zeolites, was prepared using a method similar to that of Example 3 under (2).

Example 4

Using the zeolite samples prepared in Example 3 under (1) to (5), cracking catalysts were prepared, the data of which are shown in Table III. These data show that the cracking catalysts give high hydrogen yield with good cracking activity. The catalysts were obtained by physically mixing 25% by weight of the finished zeolite into a matrix of amorphous silica-alumina hydrogel and alumina, deactivating the mixture with steam at 718 ° C., 2 bar, 100 % steam for 8 hours. Activity / selectivity tests were carried out with these catalysts with the aid of microactivity analyzes. The microactivity test was carried out under the following conditions ; n ι 482 ⁰ C ₅ weight / throughput rate: 16, ratio of catalyst to oil: 3. A gas oil starting material with a boiling range from 260 to 426 ^{0 was used} C used. The results are shown in Table III.

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Table III Catalyst composition Microactivity results

Zeolites from Example 3 {% /%) ¹⁾ Conversion, ²⁾ % by volume H ₂ ,% by weight ⁺⁾

(1) Ag-Mn-Y + (5) RE-Y (10/10) (1) Ag-Mn-Y + (2) RE-H-Y (10/10)

(3) Ag-Mn-RE-Y (12/0)

(4) Ni-Mg-Y + (5) RE-Y (4/8) (4) Ni-Mg-Y (15/0)

70.3 0.59 61, 4 0.41 64.3 0.34 65.5 0.41 55.7 0.20

% By weight of each corresponding zeolite in the zeolite / matrix mixture.

defined as the percentage of gas oil feed that is in products with a boiling point less than 204 C + coke was converted.

based on the fresh load.

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Claims (5)

UE5CKÜL.L & "s PATENTANWÄLTE WR Grace &. Co. 1114 Avenue of the Americas, New York, NY 10036 V.St.A. EUROPEAN PATENT ATTORNEYS DP. J.-D. FRHR. By UEXKULL DR. ULRICH GRAF STOLBERQ D1PL .-IN6. JÜRGEN SUCHANTKE DIPL.-ING. ARNULF HUBER DR ALLARD by KAMEKE DR. KARL-HEIN2 SCHULMEYER (Prio: April 14, 1980) (US No. 140 122) sy / do / 17562 April 1981 Process for the catalytic cracking of sulfur- and / or nitrogen-containing hydrocarbon starting materials patent claims 1. Process for the catalytic cracking of sulfur- and / or nitrogen-containing hydrocarbon feedstock, in which the starting material is used to remove the sulfur and / or nitrogen impurities hydrotreating prior to catalytic cracking in the presence of a zeolite-containing cracking catalyst is subjected, characterized in that one (a) carries out the cracking process with a catalyst with which at least 0.15% by weight of hydrogen, based on the weight of the feedstock in the resulting cracked product stream be generated, "■ '·· ■ ■"' - "- · ^: - 31U552 -I- (b) the hydrogen produced from the cracking product stream is withdrawn and isolated and (c) using the withdrawn hydrogen to treat the starting material. 2. The method according to claim 1, characterized in that that the cracking catalyst is a faujasite type zeolite with about 1 to 15% by weight of an exchanged Contains cations from the group consisting of silver, copper, nickel and / or manganese. 3. The method according to claim 2, characterized in that the zeolite with an inorganic oxide base is combined. 4. The method according to claim 3, characterized in that the base mass of silicon dioxide-aluminum oxide hydrogel, Clay, silica sol and / or alumina sol consists. 5. The method according to claim 2, characterized in that the catalyst also has a rare Contains earth-exchanged faujasite-type zeolites.